Refactor code structure and optimize performance across multiple modules

src/Provenance/__Tests/StellaOps.Provenance.Attestation.Tests/SampleStatementDigestTests.cs

@@ -57,7 +57,8 @@ public class SampleStatementDigestTests
         }
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public void Hashes_match_expected_samples()
     {
         // Expected hashes using FIPS profile (SHA-256 for attestation purpose)
@@ -69,6 +70,7 @@ public class SampleStatementDigestTests
             ["orchestrator-statement.json"] = "d79467d03da33d0b8f848d7a340c8cde845802bad7dadcb553125e8553615b28"
         };
 
+using StellaOps.TestKit;
         foreach (var (name, statement) in LoadSamples())
         {
             BuildStatementDigest.ComputeHashHex(_cryptoHash, statement)
@@ -77,7 +79,8 @@ public class SampleStatementDigestTests
         }
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public void Merkle_root_is_stable_across_sample_set()
     {
         var statements = LoadSamples().Select(pair => pair.Statement).ToArray();